How about just not compressing things for archival? A few bit errors in uncompressed files would end up as just a few bad characters. Whereas a few errors in an uncorrectable compression format might render the entire content useless. Sure they files are huge, but were talking about long term archival. In fact, if the documents are that important, have RAID-style redundancy and multiple-bit ECC in multiple geographic locations as well.
The format of the uncompressed files matters just as much in terms of bit error resilience.
Compression or not, you can always use an additional tool to produce and store extra parity data which can be used to both correct and repair bit errors, which seems like the correct answer for digital archival.
